Build light indicator
Encyclopedia
A build light indicator is a simple visual indicator used in Agile software development
to inform a team of software developers about the current status of their project. The actual object used can vary from a pressure gauge to a lava lamp
, but its purpose remains the same: to quickly communicate whether a software process (such as a 'build'
) is successful or not.
, a continuous integration tool created by employees of ThoughtWorks
. Though it primarily functioned as a web page dashboard that could report more detailed information about a build, the software could also be integrated into external devices for simpler reporting.
in a continuous integration
(CI) system. Different development teams have used different indicators, but a popular choice is the green and red lava lamp – green when the build is successful and red when something is wrong. Build lights may even be remotely accessible through a webcam
or other means. However, since many of the tests in busy development offices will always be in a state of re-test after the latest changes, some indicators have a three state
display – pass, fail and being re-tested, to provide a more nuanced indicator for staff and managers.
offer a web-accessible dashboard page and this may be permanently displayed on a wall-mounted flat screen monitor instead. The details of such a dashboard are too small to read across an office, but the colour changes present an overall picture of status.
Where several code targets, such as old product versions, are still supported for CI, but are not under such active development, then a complete dashboard may become dominated by "stale" targets that rarely change. In this case a selected dashboard may be more appropriate, where only those targets that are either failing, or are recently active, are displayed. The full dashboard is available to developer's desktops, but the wall display shows only the significant highlights. Such dashboards are often coded locally, by screen-scraping the main dashboard and applying relevant local filters to it, according to local needs. One drawback to a dynamic filtered dashboard, compared to a static dashboard, is that the position of icons for a particular target may shift on the screen, making it hard to read from across an office. In this case, distinctive icons, such as a product logo, may be displayed rather than simple colour blocks.
Agile software development
Agile software development is a group of software development methodologies based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams...
to inform a team of software developers about the current status of their project. The actual object used can vary from a pressure gauge to a lava lamp
Lava lamp
A lava lamp is a decorative novelty item that contains blobs of colored wax inside a glass vessel filled with clear liquid; the wax rises and falls as its density changes due to heating from a incandescent light bulb underneath the vessel. The appearance of the wax is suggestive of pāhoehoe lava,...
, but its purpose remains the same: to quickly communicate whether a software process (such as a 'build'
Software build
In the field of computer software, the term software build refers either to the process of converting source code files into standalone software artifact that can be run on a computer, or the result of doing so...
) is successful or not.
History
The build light indicator originated from CruiseControlCruiseControl
In software development, CruiseControl is a Java-based framework for a continuous build process. It includes, but is not limited to, plugins for email notification, Ant, and various source control tools. A web interface is provided to view the details of the current and previous builds...
, a continuous integration tool created by employees of ThoughtWorks
ThoughtWorks
ThoughtWorks is a privately owned global IT consultancy that delivers custom software, software tools, consulting, and transformation services to Global 1000 companies. It has a products division, ThoughtWorks Studios, which creates and markets software development and project management applications...
. Though it primarily functioned as a web page dashboard that could report more detailed information about a build, the software could also be integrated into external devices for simpler reporting.
Use
The traditional use of a build light is to determine the success of a software buildSoftware build
In the field of computer software, the term software build refers either to the process of converting source code files into standalone software artifact that can be run on a computer, or the result of doing so...
in a continuous integration
Continuous integration
In software engineering, continuous integration implements continuous processes of applying quality control — small pieces of effort, applied frequently...
(CI) system. Different development teams have used different indicators, but a popular choice is the green and red lava lamp – green when the build is successful and red when something is wrong. Build lights may even be remotely accessible through a webcam
Webcam
A webcam is a video camera that feeds its images in real time to a computer or computer network, often via USB, ethernet, or Wi-Fi.Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. This common use as a video camera...
or other means. However, since many of the tests in busy development offices will always be in a state of re-test after the latest changes, some indicators have a three state
Three-state logic
In digital electronics three-state, tri-state, or 3-state logic allows an output port to assume a high impedance state in addition to the 0 and 1 logic levels, effectively removing the output from the circuit...
display – pass, fail and being re-tested, to provide a more nuanced indicator for staff and managers.
Beyond single indicators
With the growth from continuous integration to continuous testing, the number of simultaneous build targets may increase, even for a single codebase. As well as a simple build (i.e. compilation) target, there will now be unit testing and various levels of system testing. As extensive tests are slow and it is desirable to keep fast tests running on a fast cycle to give rapid feedback to the developers, the number of build targets may increase to fifty or more. This is too many to show with a simple lava lamp display. Integration servers like JenkinsJenkins (software)
Jenkins, previously known as Hudson, is an open source continuous integration tool written in Java. The project renamed itself after a dispute with Oracle who claims the right to trademark the Hudson name and has applied for such a trademark as of December 2010...
offer a web-accessible dashboard page and this may be permanently displayed on a wall-mounted flat screen monitor instead. The details of such a dashboard are too small to read across an office, but the colour changes present an overall picture of status.
Where several code targets, such as old product versions, are still supported for CI, but are not under such active development, then a complete dashboard may become dominated by "stale" targets that rarely change. In this case a selected dashboard may be more appropriate, where only those targets that are either failing, or are recently active, are displayed. The full dashboard is available to developer's desktops, but the wall display shows only the significant highlights. Such dashboards are often coded locally, by screen-scraping the main dashboard and applying relevant local filters to it, according to local needs. One drawback to a dynamic filtered dashboard, compared to a static dashboard, is that the position of icons for a particular target may shift on the screen, making it hard to read from across an office. In this case, distinctive icons, such as a product logo, may be displayed rather than simple colour blocks.